Petal (4)
I believe the answer is:
leaf
'petal' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for leaf that I've seen before include "Two pages of a book" , "Bit of foliage" , "Frond" , "Organ of photosynthesis in plants" , "Part of tree or book" .)